Web former with wear insert



Dec. 30, 1969 J. B. TANNER WEB FORMER WITH WEAR INSERT Filed June 25,1967 m/vEA/me, J/ICK B. 774A A 5/2 United States Patent 3,486,424 WEBFORMER WITH WEAR INSERT Jack B. Tanner, Decatur, Ga., assignor to TheWoodman Company, Inc., Decatur, Ga., a corporation of Georgia Filed June23, 1967, Ser. No. 648,269 Int. Cl. B31b 1/38 U.S. C]. 93-82 9 ClaimsABSTRACT OF THE DISCLOSURE A device for transforming a web into a tubeutilizing a winged former with a wear insert position within the bodythereof to receive substantially the full frictional wearing force fromsaid web. The insert is adjustable along the longitudinal axis of theformer and undersized inserts can be utilized to form tubes of smallerthan normal size.

The present invention generally relates to form and fill packagingmachines and, more particularly, to an improved tube former specificallyadapted for such machines.

Packaging machines of the form and fill type now almost universallyemploy a former for transforming a web of sheet material into acontinuous tube which includes an upright tubular body and a collar-likepreformer portion extending at an acute angle to said body. As is wellknown, the web is drawn up over the preformer portion and then reverselydirected down through the tubular body for the transforming operation.This type of former has certain advantages over other devices of thistype in that the transformation into a tube can be' made without formingwrinkles in the sheet material and without the necessity of employinginternal guide mandrels thereby leaving the full opening ofthe top ofthe tube for positioning of the filling tube for an unrestricted productfilling operation. However, since the sheet material is drawn withrather great force over the direction reversing line of transformationbetween the guide portion and the tubular body and since the sheetmaterial inherently has at least some degree of abrasiveness, thisjunction between the guide portion and the tubular body is subjected toan appreciable amount of wear.

Prior to the present invention, after an extended period of use theformer would have to be removed from the machine and replaced with a newformer or repaired in this critical area of the junction where theactual transforming operation occurs. Because of the variation in theangle at which the sheet material passes over the line oftransformation, the wear on the former is generally uneven, with thegreatest wear being at the crown of the upper edge of the tubular body,which makes the repair procedure highly time consuming and tedious and,at best, results in a former that is serviceable for only a fraction ofthe time of a new former. In either case, substantial expense isinvolved in these prior procedures and thus it would be desirable toprovide an improved former and procedure for meeting this problem.

Accordingly, it is one object of the present invention to provide aformer of the type described having a removable wear insert whichreceives substantially the full frictional wearing force caused by thetransforming operation.

It is another object of the present invention to provide a former havinga winged preformer portion wherein a wear insert of the type describedis provided to substantially prevent contact and resulting wear by theweb of the critical guiding areas of the former and preformer portion soas to alleviate the problem of replacement and repair.

It is still another object of the present invention to provide thedescribed type of tube former with a wear insert, which insert can beeasily adjusted within the former so that the position of the guide lipof the insert can be set for maximum forming efiicieney and so that theinsert may be periodically repositioned within the former to present anew, and preferably reshaped, guide lip.

Briefly, the device of the invention comprises a wear insert of tubularshape which is fixedly positioned within the tubular body of aconventional former so as to receive the wear from the web in thecritical areas. The guide lip of the insert has been found to be capableof receiving a very large proportion of the total wear of the former andwhen it has been worn from its original shape so as to threaten theefficiency of the tube forming, operation, all that is necessary is thatthe insert be removed from the former and replaced with a new insert ofthe same size having a properly shaped or contoured guide lip. Thisconcept means not only a saving in time for the user or operator of themachine, but also obviously represents a sizable saving in cost due tothe relatively simple and inexpensive construction of the tubularinsert, as compared to the complete former.

In accordance with another feature of the present invention, the insertmay be made adjustable along the longitudinal axis of the tubular bodyso that as the profile of the guide lip wears, the insert may berepositioned upwardly to compensate for the wear. Because the wearacross the profile of the guide lip is usually not even, it has beenfound to be preferable to remove the worn insert completely and replaceit with another insert which has previously been reshaped as required.It will be realized that due to this adjustable feature, the insert maybe positioned in the required relationship with the former so that thesame insert may be reshaped and used several times.

Because the insert is of a simple tubular shape, it has been found to bemore easily and successfully coated with materials having improvedfriction and wearing properties as is desired. For example, the insertmay be coated with chromium or other metallized materials as well asceramic materials without the usual risk of distortion of the metal andthus destruction of the critical curved portions of the former andpreformer. Indeed, an insert of the present invention can be coated witha hard ceramic surface that registers on the order of 9.5 on Mohs scalewithout distortion; whereas, heretofore the risk of causing distortionand thus destruction of the complete former has limited the hardnessobtainable to at least one unit of measurement lower. With the insertthus coated with a hard ceramic coating, in addition to the wearproperties of the former being enhanced, the force required to pull theweb through the former is reduced significantly by reduction infriction, both at the guide lip and along the interior of the insert.Also, of course, the coating of the insert is significantly less interms of cost than is involved in coating the entire former, andobviously other coatings, such as the new poly-silicone plastics, forexample the plastic 3 sold under the trade name Teflon by E. I. du Pontde Nemours and Company, Wilmington, Del., could be substituted for theceramic or metallized coating, if desired.

Still another aspect of the present invention is concerned with the easeof adaptation of a former with the inventive insert for making differentsize tubes. This is accomplished by simply using a smaller size insertin a larger or nominal size former so that a range of sizes of tubes,within at least up to one inch less than the nominal size, may be formedwith a single former. With this arrangement the changeover of themachine for different but closely related bag sizes is more efiicientand less costly to the operator since he needs to have on hand only thedifferent size inserts for use with the same former. When the insertbeing used is of a smaller size, stabilizing spacers may be placedbetween the sides of the insert and the sides of the former to insure asmooth transformation. Further in the preferred embodiments shownherein, the guide lip is purposely squared off so as to form transitorycreases across the web and thereby induce longitudinal smoothing of thesame.

Still other objects and advantages of the present invention will becomereadily apparent to those skilled in this art from the followingdetailed description, wherein I have shown and described only thepreferred embodiment of the invention, simply by way of illustration ofthe best mode contemplated by me of carrying out my invention. As willbe realized, the invention is capable of other and differentembodiments, and its several details are capable of modification invarious obvious respects, all without departing from the invention.Accordingly, the drawings and description are to be regarded asillustrative in nature, and not as restrictive.

In the drawings:

FIGURE l is an overall side view of the specific area of a form and fillmachine in which the former of the present invention can be utilized;

FIGURE 2 is an exploded view of a former with winged preformer portionand an insert to be positioned within said former constructed inaccordance with the teachings and principles of the present invention;

FIGURE 3 is a front view of the assembled former and insert of FIGURE'2;

FIGURE 4 is an enlarged detailed view taken alOng line 4-4 of FIGURE 3;and

FIGURE 5 is a top view of a former with an undersized insert positionedtherein for forming a smaller than nominal size tube.

With specific reference now to the drawings for a more detailedexplanation of the present invention and its environment, in FIGURE 1there is illustrated a tube forming station of a conventional form andfill packaging machine wherein a web W of sheet material moves over aseries of guide rolls R from the supply roll (not shown) and then intosaid forming station. The forming station itself includes a former,generally designated by the reference numeral 11, which is operative toform the web W into a continuous tube by a suitable sealing means, asindicated at 12 in the drawings. As is well known in the form and fillpackaging art, a transverse seal 13 is then formed across the tube 12,the partly formed package filled with product through said tube, and asimilar seal then formed above the seal 13 to complete the package.

The former 11 specifically illustrated to describe the inventionincludes an elongated, open front tubular body 15 mounted in a generallyupright position on a base member 16 having suitable mounting apertures17 and a winged preformer 18 intersecting the upper limit portion ofsaid body 15 at an acute angle thereto. This intersection of thepreformer 18 and the body 15 forms a contoured juncture 19, which in theillustrated embodiment extends around less than the full periphery ofsaid body 15 because of its open front. Thus, in prior art formers ofthis type this juncture 19 thus forms, partially at least, the line oftransformation of the web, i.e. the point at which said web is reverselydirected and shaped into the tube. It should be noted at this pointthat, in fact, if a web were passed over only this part of the completeformer 11 of the present invention, it would be reversely directed downinto the body 15 from the pref-ormer 18 and a tube would be formed,although somewhat less efficiently, so that for purposes of descriptionthe juncture 19 can be referred to herein as a nominal line oftransformation. Thus, insofar as the structure which has been recited tothis point in this detailed portion of the description, this type offormer 11 can be considered in itself to be well known in the art, andtherefore it should be understood that the device of the invention nowto be described could be equally well adapted for use with other formersof this type having a different shape in the body 15 and/or contour ofthe juncture 19.

With this proposition in mind, there is shown in FIG- URE 2 a wearinsert 25 in an unmounted position above the former 11 ready to beinserted therein for use. The wear insert 25 is of tubular shape and isdesigned in this particular embodiment to substantially conform to ormate with the inside surface of the tubular body 15. The guide ears 26,27 on the front of the wear insert 25 are designed to make the finallaying of the web together for forming of the longitudinal seam of thetube at 12 as is known.

In accordance with an important aspect of the invention, the wear insert25 has a contoured guide lip 28 formed by the upper edge thereof and inthe embodiment shown said lip 28 extends down in a continuous fashion onsaid guide ears 26, 27 to perform the final laying operation justmentioned. Since the web W passes up and over the former 11 in itsassembled condition (FIGURE 3), it will be realized that this continuousguide lip 28 thus forms the actual line of transformation of the web, ascan best be seen from viewing the cross section of FIGURE 4. As has beenindicated, it has been found that the greatest and perhaps the onlyappreciable wear in a former of this type occurs along this actual lineof trans formation; that is, Where the web is reversely directed fromguided, face-to-face contact with the preformer 18 into the tubular body15. Also, it has been proven that of this wear, the largest amountoccurs at a crown 29 (FIGURE 2) of this actual line of transformation,or at the highest point or apex of the contoured intersection betweenthe two joining surfaces. Thus, because the actual line oftransformation is formed at the guide lip 28 of wear insert 25, any wearof the type described above occurs at this point whereby the former 11of the invention can be simply renewed by just incorporating a newinsert 25 with a properly shaped and contoured guide lip 28 whereuponnormal, efficient operation is immediately insured.

The cross-sectional profile of the guide lip 28 is preferably squaredoff, as can be seen in FIGURE 4, for the purpose of causing successivetransitory angular creases c 0 in the web W during transformation. Thesepronounced creases c 0 in the web W tend to cause an improvedlongitudinal stretching of the structural molecules within the sheetmaterial thereby tending to straighten the web W to remove any curl thatmight have been present as a result of said web W being stored in aroll. Also, this sharp turning action and molecular stretching action isof importance in the present combination to positively prevent wrinklingof said Web W in the longitudinal direction by more forcibly inducingthe web W to spread out in the transverse direction or around the guidelip 28, as is desired.

For the purpose of allowing accurate adjustment of the guide lip 28 ofwear insert 25 with respect to the juncture 19, there is provided meansfor adjusting the wear insert 25 along the longitudinal axis of thetubular body 15, as compositely shown in FIGURES 2-4. This meanspreferably comprises a countersunk aperture 30 formed in the wear insert25 (FIGURE 2), a corresponding elongated slot 31 formed in the rear ofthe tubular body 15 (FIGURES 2 and 4) and a cooperating fastening meansincluding a machine bolt 32 and nut 33. It will be realized that thisarrangement allows the wear insert 25 to be fixedly clamped against therear of the interior of said body 15 once the proper adjusted positionhas been located. Furthermore, as wearing of said guide lip 28 occursthis adjusting means may be utilized to raise the insert 25 upwardly torelocate the guide lip 28 in its proper position to most favorablyengage the web W. Preferably, since the wear insert 25 may be easilyremoved from the former 11, when an adjustment is necessary said insert25 is first removed from the body 15 and the guide lip 28 is reshapedfor the proper contour and to give the advantageous squared offcross-sectional profile for the purposes described above and then saidinsert 25 is replaced and readjusted as required.

The most advantageous or proper position of the wear insert 25 is shownin FIGURE 4 and is such that the guide lip 28 is slightly above and tothe inside of the juncture 19 so that as the web passes up and over thepreformer 18 it avoids contact with said juncture 19 and is thenstretched and reversely directed into the interior of said insert 25. Asshown in FIGURE 3, the proper position of the guide lip 28 is in thisposition of slightly above the juncture 19 around the full periphery ofsaid guide lip 28; however, since the intersection angle is more acuteat the rear of the former 11 than at the front, the actual extent abovethe juncture 19 is progressively less at the front of the former. Thus,the path of the web W is such as to make a smooth transition fromcontact with the preformer 18 to engagement with the guide lip 28, as iswell indicated in FIGURE 4.

In view of the foregoing, it can be realized that the use of the wearinsert 25 to receive substantially the full frictional wear force of theweb W offers distinct advantages over the prior art in that not only thecost of repair and replacement is reduced but because a more eflicientforming action is realized. Further advantages previously mentioned stemfrom the fact that the interior wear surface of the wear insert 25 andthe lip 28 itself may be easily coated with friction reducing materialswithout fear of distorting or warping the critical contour along thejuncture 19 and the guiding surfaces of the preformer 18 and the body25, as has been a problem in the past. Furthermore, of course, suchcoating can be carried out more economically on the insert alone, alsoas has been noted above.

In order to use the former 11 to make tubes smaller than the nominalsize of said former 11 in accordance with the present invention, theoperator need only select a wear insert 25a which is smaller than thetubular body 15, as shown in FIGURE 5. The insert 25a may thus befixedly attached to the rear of the tubular 'body 15 where it isfrictionally held in position essentially as before. In operation, theweb W passes up and over the preformer 18, spans the gap between thejuncture 19 and the guide lip 28, and then is transformed into a tubealong the line of transformation formed by the guide lip 28a (noteFIGURE In order to assure complete stabilization of the sides of theformer 2511, it may be necessary or desirable to provide side spacers35, 36 to brace the same against the interior of the tubular body 15. Asbefore, the positioning of the guide lip 28a is such that the web Wavoids the juncture 19 forming the nominal line of transformation sothat substantially the full frictional wear is realized at said guidelip 28a.

Other embodiments and modifications of the device of the presentinvention are immediately apparent and include, for example, thepossible use of a plurality of nested inserts within the interior of thetubular body 15 to render the actual line of transformation of theinnermost insert concentric with the nominal line of transformation. Inthis case, one or more inserts would be removed as required by the sizeof tube desired to be formed.

In either case, it has been found to be practical to utilize theundersized inserts 25a up to one inch less in diameter than the tubularbody 15.

In this disclosure, there is shown and described only the preferredembodiment of the invention, but, as aforementioned, it is to beunderstood that the invention is capable of various changes ormodifications within the scope of the inventive concept as expressed bythe accompanying claims.

I claim:

1. The combination of a former for transforming an open web of sheetmaterial into an elongated continuous tube by movement of said webthrough an acute angle over said former including a tubular body and aweb preformer portion extending at said acute angle to said body forminga juncture with said body and for guiding said open web of sheetmaterial, and a wear insert fixedly positioned on said tubular body andextending around substantially the full periphery of said juncture, saidinsert being on the exterior of said continuous tube and injuxtaposition thereto, said insert being within the interior of saidbody and over which said web passes so as to be located between saidbody and said web to substantially prevent wear of said juncture andsaid interior by said web during the transforming operation, said inserthaving a guide lip spaced above said interior of said body, and overwhich said web moves for the transforming operation of said open webinto said tube whereby the actual line of transformation for said web isspaced from the nominal line of transformation of the former located atsaid juncture.

2. The combination of claim 1 wherein is further provided means foradjusting said wear insert along the longitudinal axis of said bodywhereby said guide lip of said insert may be repositioned with respectto said juncture to compensate for any wear.

3. A former assembly for transforming an open web of sheet material intoan elongated continuous tube by movement of said web through an acuteangle over said former assembly comprising a tubular body, a dependingcollar-like preformer intersecting said body at said acute angle along acurved juncture, said preformer being shaped to direct said open web ofsheet material toward said juncture formed by the intersection, and awear insert positioned on said tubular body and extending aroundsubstantially the full periphery of said juncture, said insert being onthe exterior of said continuous tube and in juxtaposition thereto, saidinsert being within the interior of said body between said body and saidweb to guide said web, a guide lip on said insert defining the line oftransformation of said open web into said tube and receivingsubstantially the full frictional wearing force caused by saidtransforming operation, said guide lip being spaced above said interiorof said body and over which said web passes to form said transformationline spaced from said preformer and said body, whereby saidtransformation line is also spaced from said juncture.

4. A former for transforming an open web of sheet material into anelongated continuous tube by movement of said web through an acute angleover said former comprising a web preformer extending at said acuteangle to the longitudinal axis of said continuous tube, the openpreformed portion of said web at said preformer forming a transformationline with said continuous tube, a support body positioned adjacent tosaid continuous tube and said preformer, a wear insert fixedlypositioned on said support body and extending around substantially thefull periphery of said line, said insert being positioned on theexterior of said continuous tube and in juxtaposition thereto, said webpassing over said insert whereby said insert is located between saidbody' and said web to substantially receive the entire wear caused bysaid transformation line in said web during the transforming operationof said open preformed portion into said tube, said insert having aguide lip extending above said preformer to form said transformationline spaced from said preformer and said body.

5. The combination of claim 4 wherein is further provided means foradjusting said wear insert along said 1ongitudinal axis of said tubewhereby said guide lip may be repositioned upwardly to compensate forany wear.

6. The combination of claim 3 wherein the corresponding sides of saidinsert are spaced radially inwardly toward said longitudinal axis fromthe sides of said body whereby the transformed tube is smaller than thenominal size of said former.

7. The combination of claim 6 wherein is further provided spacerspositioned between said wear insert and said body whereby said wearinsert is stabilized.

8. The combination of claim 5 wherein said adjusting means comprises alongitudinally extending slot formed in said body at a locationunderlying the center line of said web, a corresponding aperture formedin said insert, and locking means passing through said aperture and saidslot for clamping said insert against the interior surface of said bodyfor frictionally holding the same in position.

9. The combination of claim 3 wherein said guide lip is squared off toform at least 2 successively pronounced transitory creases across saidweb at said actual line of transformation to induce longitudinalsmoothing of said Web.

References Cited UNITED STATES PATENTS 3,122,072 2/1964 Monsees 93-823,125,008 3/1964 Herdina 9382 3,155,018 11/1964 Kirsten 9382 3,267,8228/1966 Harrison 9382 3,296,770 1/1967 Wilson 93-82 X 3,370,517 2/1968Vichos 9382 2,951,322 9/1960 Wood 9320 X 3,415,171 12/1968 Wilson 9382FOREIGN PATENTS 1,311,341 10/1962 France.

WAYNE A. MORSE, 111., Primary Examiner US. Cl. X.R. 5328; 9320

